Active-time dependent bias current generation for switched-capacitor circuits

An apparatus, comprising:

• a first phase signal and a second phase signal operating at a sampling rate, wherein an asserted time of the first phase signal and an asserted time of the second phase signal are separated by a predefined non-overlap time;
• a bias generator configured to generate an adaptive bias current responsive to the asserted time of the first phase signal, the bias generator comprising:
• a bias amplifier comprising an inverting input operably coupled to a reference voltage, a non-inverting input, and an output;
• a feedback switch controlled by the first phase signal with a first side coupled to the output of the amplifier;
• a frequency dependent impedance coupled to a second side of the feedback switch and configured as a switched capacitor network operating at a same frequency as the first phase signal;
• a feedback signal coupled between the second side of the feedback switch and the non-inverting input of the amplifier;
• and
• and a current mirror operably coupled to the output of the amplifier to generate the adaptive bias current;
• a plurality of switched capacitors operably coupled to the first phase signal and the second phase signal;
• and
• an amplifier operably coupled to the plurality of switched capacitors and the adaptive bias current and having a response time inversely proportional to the adaptive bias current.

A method comprising:

• generating a first phase signal and a second phase signal, both operating a sampling rate, wherein an asserted time of the first phase signal and an asserted time of the second phase signal are separated by a predefined non-overlap time;
• operating a switched-capacitor circuit with the first phase signal and the second phase signal, the switched-capacitor circuit having a bandwidth proportional to an adaptive bias current;
• and
• generating the adaptive bias current inversely proportional to an asserted pulse width of the first phase signal, the adaptive bias current adaptable to support a first bandwidth of a first communication mode and a second different bandwidth of a second different communication mode.

An apparatus comprising:

• means for generating a first phase signal and a second phase signal, both operating a sampling rate, wherein an asserted time of the first phase signal and an asserted time of the second phase signal are separated by a predefined non-overlap time;
• means for operating a switched-capacitor circuit with the first phase signal and the second phase signal, the switched-capacitor circuit having a bandwidth proportional to an adaptive bias current;
• and
• means for generating the adaptive bias current inversely proportional to an asserted pulse width of the first phase signal, the adaptive bias current adaptable to support a first bandwidth of a first communication mode and a second different bandwidth of a second different communication mode.